My girlfriend got her period on December 13th. And I'm guessing she was suppose to get it again this pass friday, January 11th (27days later), but she hasnt. Then sunday morning we had sex, and she started bleeding. For like 10mins (20max). It was a light color, but I'm not sure cuz it also was mixed because she cum. I'm not sure if this is normal. I read somewhere that she could have had a abrasion from intercourse because she wasnt wet enough because we didn't go that long because I saw that. Can I just get like...all the possibilites that it could be.